Wednesday 4 June Moab, UT

Again another two-night stopover.
Moab is a perfect hub for this region and perfect for a number of other reasons, too!

Today we went to:

Island in the Sky
Is still forming and yet dissolving at the same time!
We arrived at the Grand View Overlook to rain, which was due for this afternoon but arrived early!
The view from Needles overlook with warm, clear sunny skies would have been the thing to see, not this dull, flattened and vague landscape – pah!

Several mysteries remain unanswered in the Canyonlands NP, the most striking of which is that of the ‘Upheaval Dome’
The Upheaval Dome is an anomaly in the relative geologic order of canyon country. Here, rock layers are dramatically deformed in a roughly circular or “bull’s-eye” pattern nearly three miles across.
Geologists are unsure of its origin and two main and distinct theories are hotly debated.
Impact Crater Theory: When meteorites collide with the earth, they leave impact craters.
Some geologists estimate that 60-160 million years ago, a meteorite 500 to 1000 feet across hit the earth at what is now Upheaval Dome.
The impact created a large explosion, sending dust and debris high into the atmosphere.
The impact initially created a crater, which then collapsed as gravity took over. In this rebound stage, rock layers were thrust inward and upward to fill the void left by the impact.
Erosion since the impact has washed away any meteorite debris and other tell-tale evidence of impact.
I’m not convinced!
Salt Dome Theory: A thick layer of salt, formed by the evaporation of ancient landlocked seas, underlies much of southeast Utah and Canyonlands National Park. When under pressure from thousands of feet of overlying rock, the salt can flow plasticly, like ice moving at the bottom of a glacier.
In addition, salt is less dense than sandstone and other sedimentary rocks.
As a result, over millions of years salt can flow up through rock layers as a “salt bubble”, rising to the surface, creating salt domes that deform the surrounding
rock.
Again I’m not convinced, but its more likely!

I’m more of the view that this was some minor magmatic stack which simply blew itself out after finding a way through the salty layers to the rock surface. There remains a molten spire at the centre of the jagged dome layers now.
If there had been a massive meteorite impact, clasts of molten debris would be flung hundreds of miles in all directions – so far, no such debris has been located. Also the impact site would have been more vapourised by the immense heat arising from such an impact.
Thirdly, there is no evidence to indicate a foreign body was involved here. Its true some particles of rock exhibit magnetic tendencies, but that is so for much of this permeable sandstone which is drenched and coloured red by iron oxide – a magnetic compound itself!
Lastly, there have been no rocks from this region, discovered in far-flung areas which would have been the case if an impact had occurred.
Case still open, I’m afraid!

On our way back we drove towards the small hamlet of Potash to see some more work by man’a hand, more petroglyphs on rock by the side of the small UT-279.
Interesting, with what appears to be fencing, railroad or counting symbols.
Each of the human figures seems to be carrying a bowl or round object – a space helmet perhaps….??!!

Journey details and Notes
Distance: 92 miles
Time: 8 hrs 25 mins
Weather: Overcast and raining intermittently and often